Arrangement for attaching a brake force booster

ABSTRACT

The present invention discloses an arrangement for attaching a brake force booster, that is operable by a push rod, to the splashboard of an automotive vehicle by means of an adapter, wherein a sealing element is interposed between the adapter and the splashboard which additionally is in a radially sealing abutment with the push rod. 
     In order to ensure the correct positioning of the sealing element during the assembly of the brake force booster, the present invention arranges for the brake force booster to include at least one connecting bolt having attaching elements at its ends for attaching the brake force booster to the adapter and for attaching a master brake cylinder connected downstream of the brake force booster to the booster housing, and the adapter has at least one recess which accommodates the attaching element associated with it, and the sealing element includes at least one guide bush which is adapted to be slipped on the attaching element.

TECHNICAL FIELD

The present invention relates to an arrangement for attaching a brakeforce booster generally relates to brakes and more particularly to thesplashboard of an automotive vehicle

BACKGROUND OF THE INVENTION

A fixing arrangement of this general type is disclosed in German patentapplication No. 38 03 958. The adapter of the prior art fixingarrangement partly encloses the housing of the brake force booster, andthe protective cap which is used as a seal has two radial attachmentareas which are squeezed in between the adapter and the splashboardafter the assembly of the brake force booster. The adapter favorablyincludes a ventilation passage that permits aspirating the air which isrequired for a proper functioning of the brake force booster.

However, a disadvantage of the prior art arrangement is the ease inwhich the protective cap may be lost prior to final assembly therebyimpairing the desired sealing effect between the adapter and thesplashboard.

An object of the present invention is to disclose an arrangement forattaching a brake force booster which permits an accurate positioning ofthe sealing element during the assembly and, thus, a reliable sealing ofthe adapter in relation to the splashboard.

According to the present invention, this object is achieved in that thebrake force booster includes at least one connecting pin having at itsends attaching elements for attaching the brake force booster to theadapter and for attaching a master brake cylinder connected downstreamof the brake force booster to the booster housing, in that the adapterincludes at least one recess which accommodates the attaching elementassociated with it, and in that the sealing element has at least oneguide bush which is adapted to be slipped on the attaching element.

In a preferred aspect of the present invention, the seal is provided asa pleated bellows. This provision permits replacing previously used,properly sealed filter elements disposed in the control housing of thebrake force booster for noise damping by simple filter elements whichare only used for filtering dust. The result is that the response timesof the brake force booster are considerably shortened. The filterelements can favorably be arranged between the part of the boosterhousing which projects into the inside space of the adapter and theinside wall of the adapter.

Preferably, the pleated bellows has two symmetrically opposite radialattachment areas which cooperate with attaching elements fitted to theadapter. This provision permits effectively retaining the pleatedbellows during transport as well as an additional sealing in the area ofthe attaching elements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a longitudinal cross-sectional view of an embodiment of theattaching arrangement of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a brake force booster 1 fastened to a splashboard 6 (shownonly schematically) of an automotive vehicle splashboard (not shown) bythe intermediary of an adapter 3. Brake force booster 1 is fitted to theleft-hand side of the adapter, as viewed in the drawing. The adapter 3which includes a ventilation passage 7 has two oppositely arranged screwbolts on its side close to the splashboard 6 which pass throughcorrespondingly configured openings in the splashboard 6 and cooperatewith screw nuts (not shown) . The screw bolt 9 shown in the drawing isdesignated by reference numeral 9. The ventilation passage 7 whichpermits a quick ventilation of the brake force booster 1 is formed by aradial recess in the adapter wall in this embodiment. Interposed betweenthe splashboard 6 and the adapter 3 is a seal 4 which is configured as apleated bellows 8 in the embodiment shown. A push rod 5 is passedthrough the end of the pleated bellows 8 remote from the adapter 3.Coupled to a (non-illustrated) brake pedal, push rod 5 is used toactuate the brake force booster 1. Further, the pleated bellows 8includes in its interior several radial knubs 23 or webs which bearagainst a control housing 24 that receives a control valve 25 of thebrake force booster 1.

To attach the brake force booster 1 to the adapter 3, two rod-shapedconnecting pins 10, 11 are used which are arranged in parallel to thelongitudinal axis of the brake force booster so that they interconnecthousing halves 12, 13 that form a booster housing 20. On the ends of theconnecting pins 10, 11, illustrated on the left in the drawing, firstattaching elements 14, 15 are provided, the purpose of which is toattach a master brake cylinder (not shown) that is connected downstreamof the brake force booster 1. On the ends of the connecting pins 10, 11shown on the right hand in the drawing, second attaching elements 16 areprovided which serve for the attachment of the booster housing 20 on theadapter 3 and are received in cylindrical recesses 17,—in the adapter 3.

Further, the pleated bellows 8 has a radial collar 21 at its end closeto the adapter 3. The side of collar 21 remote from the splashboard 6has an annular bead 18 which is received in an annular groove 19provided in the adapter. Projecting from collar 21 are two radiallyoppositely arranged attaching lugs (not shown) which include openingsfor the screw bolts 9, to pass through. Also, guide bushings 22 whichextend axially in the direction of the brake force booster 1 are formedon the periphery of the collar 18 in a manner preferably offset by 90°in relation to the attaching lugs. The outside diameter of guidebushings 22 corresponds to the diameter of the above-mentioned recesses18. In the assembled condition of the brake force booster 1, bushings 22are slipped on attaching elements 16, associated with the adapter 3.

What is claimed is:
 1. System for attaching a brake force booster, thatis operable by a push rod, to a splashboard of an automotive vehicle,comprising: an adapter, a sealing element interposed between the adapterand the splashboard which said sealing element including an opening isin a radially sealing abutment with the push rod, at least one attachingelement for attaching the brake force booster to the adapter wherein theadapter includes a mating recess for accommodating the attachingelement, wherein the sealing element has at least one guide bush whichis adapted to be slipped on the attaching element.
 2. Arrangement asclaimed in claim 1, wherein the attaching element is arranged on a firstend of a connecting pin and attaches the brake force booster to theadapter, wherein the connecting pin has a second end for attaching amaster brake cylinder to a booster housing.
 3. Arrangement as claimed inclaim 1, wherein the sealing element further includes a pleated bellows,and the guide bush arranged in a radial fringe area or a collar thereof.4. Arrangement as claimed in claim 3, wherein the pleated bellows has aradially circumferential annular bead which is adapted to be placed intoa radially circumferential annular groove of the adapter.
 5. Arrangementas claimed in claim 1, wherein the pleated bellows has two oppositelyarranged radial attaching lugs which cooperate with attaching elementsor screw bolts fitted to the adapter.
 6. Arrangement as claimed in claim5, wherein the pleated bellows has in its interior a plurality of radialknubs or webs which bear against a control housing that accommodates acontrol valve of the brake force booster.